The growing stringency of the requirements for safety in the driving, operation and use of modern vehicles calls for the devotion of increasingly greater efforts of monitoring the driving status of the vehicle. Accordingly, in vehicle transmissions with automatic or automated gear change or transmission change, the monitoring of transmission slippage is part of the state of the art. Inadmissible slippage in the transmission, which originates from other than the process of gear or transmission change, is typically determined by way of a simple plausibility check of the transmission rpm and/or transmission ratios. Inadmissible slippage in the transmission which originates during a gear or transmission change is typically determined by monitoring rpm characteristics or by requiring compliance with transmission rpm and/or transmission tolerance ranges. In both cases, the signals of rpm sensors at the transmission input and at the transmission output are typically analyzed for this purpose. An automatic transmission with a torque converter inserted in the flow of forces between the vehicle drive motor and the transmission as a drive start-off element, for example, typically exhibits a turbine rpm sensor at the transmission input and an output-side rpm sensor at the transmission output. In order to be able to determine transmission slippage at all, in any event, minimum measurable rpm values are necessary, as a function of the specific type of rpm recording system used (sensor type, pulse series and/or interval between pulses). This way that, according to the state of the art, the vehicle, in any event, must move at a certain minimum velocity to produce measurement signals that can be analyzed for the purpose of gear and/or transmission monitoring.
The objective of the present invention is to present a process by way of which, at near-zero speeds, it is possible to monitor whether the preselected direction of travel and/or the direction of frictional drive from the transmission, engaged by the driver of the vehicle, is identical to the actual direction from frictional drive of the transmission.